nixpkgs/nixos/modules/tasks/filesystems/cifs.nix

{ config, lib, pkgs, ... }:

with lib;

let

  inInitrd = config.boot.initrd.supportedFilesystems.cifs or false;

in

{
  config = {

    system.fsPackages = mkIf (config.boot.supportedFilesystems.cifs or false) [ pkgs.cifs-utils ];

    boot.initrd.availableKernelModules = mkIf inInitrd
      [ "cifs" "nls_utf8" "hmac" "md4" "ecb" "des_generic" "sha256" ];

    boot.initrd.extraUtilsCommands = mkIf (inInitrd && !config.boot.initrd.systemd.enable)
      ''
        copy_bin_and_libs ${pkgs.cifs-utils}/sbin/mount.cifs
      '';

    boot.initrd.systemd.extraBin."mount.cifs" = mkIf inInitrd "${pkgs.cifs-utils}/sbin/mount.cifs";

  };
}